Add test for Chromium crash when a GPU buffer is deleted

When preserveDrawingBuffer is true and WebGL context leaves a vertex
attribute array != 0 enabled while deleting the buffer attached to that,
Chromium's (at least up to version 33) GPU process will crash when
copying the WebGL drawing buffer. Reproduces at least on NVIDIA OpenGL
drivers.
related to pull request #451: added needed check also for versions 1.0.1 and 1.0.2
Expand float texture extension tests to test rendering to RGB textures

Also fix incorrect alpha values in the expected values in the test and
some minor things in presenting test results.
Merge pull request #463 from imzet/utils-vbo-use-prev-versions

related to pull request #451: added needed check also for versions 1.0.1...
Merge pull request #464 from NVIDIA/expand-oes-texture-float-test

Expand float texture extension tests to test rendering to RGB textures
Add GPU buffer deletion test to test list
Merge pull request #462 from NVIDIA/bufferdata-delete

Add test for Chromium crash when a GPU buffer is deleted